1. Field of the Invention
The present invention relates to an ultrasonic sealing method and device that clamps a bag from both sides by a horn and an anvil of an ultrasonic sealing device, and ultrasonic vibration energy transmitted from the horn seals films on both sides of the bag together or seals the films on both sides of the bag and a part, such as a spout, sandwiched therebetween.
2. Description of the Related Art
Patent Literature 1 to 3 disclose rotary bag-filling packaging machines. The rotary bag-filling packaging machine disclosed therein includes a plurality of pairs of grippers that are moved along an annular movement path. As the grippers make one rotation along this movement path, bags are supplied successively to the grippers, their side edges are held by the grippers so that the bags hang down with their mouths facing up, and then the bags are conveyed along a specific conveyance path. In these rotary bag-filling packaging machines, various packaging steps are successively carried out in the course of the bag conveyance, including a step of opening the bag mouth, a step of filling the bag with its contents, and a step of sealing the mouth. Also, in these rotary bag-filling packaging machines, the mouth sealing step is performed by an ultrasonic sealing device.
Patent Literature 4 discloses a rotary spout insertion and sealing apparatus (that manufactures a bag equipped with a spout (called “spouted bag”). This rotary spout insertion and sealing apparatus includes a plurality of spout holding members that are intermittently moved along an annular movement path. As the spout holding members make one rotation along this movement path, spouts are successively supplied to the spout holding members, these spouts are held vertically by the spout holding members, and then the spouts are conveyed along a specific conveyance path. In this rotary spout insertion and sealing apparatus, an insertion and temporary sealing step (in which a bag is supplied to a spout that is held by the spout holding members, the lower portion of the spout (such lower portion will be called “to-be-sealed portion”) is inserted into the mouth of the bag, and then the films and the to-be-sealed portion are temporarily sealed together), a step of performing main sealing one or more times (in which the sealing of the films on both sides of the bag as well as the sealing of the to-be-sealed portion with the films on both sides are performed simultaneously), and a step of cooling the seal are successively carried out in the course of this conveyance. Patent Literature 4 further discloses that this rotary spout insertion and sealing apparatus fills the spouted bags thus obtained with their contents on the above-described conveyance path. The main sealing step is carried out by clamping the bag mouth from both sides of the bag between a pair of hot plates (the to-be-sealed portion of the spout is sandwiched between the films on both sides).
Patent Literature 5 to 7 disclose gas trapping method and apparatuses for a bag that has a gas compartment which extends in the longitudinal direction and is integrally formed at the sealed part on the side edge of the bag. A hole or cutout that allows the outside of the bag to communicate with the interior of the gas compartment is formed in the film of a gas introduction portion of the gas compartment. A pressurized gas is blown into the gas compartment of the bag, and the gas is trapped in this gas compartment. The gas trapping apparatuses of Patent Literature 5 to 7 include a plurality of pairs of grippers that are moved intermittently along an annular movement path, and as the grippers make one rotation along the movement path, the bags are successively supplied to the grippers, their side edges are held by the grippers, and then the bags are hanged down and conveyed along a specific conveyance path with the mouths of the bags facing up. A gas-blowing-in step (in which a nozzle is provided to the gas introduction portion and pressurized gas is blown into the interior of the gas compartment), a blocking step (in which the flow of gas into the gas compartment and the gas introduction portion is blocked off), and a gas trapping step (in which the gas introduction portion or the nearby area is sealed so that the gas is trapped inside the gas compartment) are successively performed in the course of the conveyance. The gas trapping step is performed by clamping the gas introduction portion or the nearby area of the bag from both sides with a pair of hot plates.
Furthermore, the specification and drawings of Japanese Patent Application 2014-99452 (Japanese Patent Application Laid-Open (Kokai) No. 2015-214366 that corresponds to the U.S. patent application Ser. No. 14/710,339 (U.S. Patent Application Publication No. 2015/0328855)) disclose an invention in which a horn and an anvil of an ultrasonic sealing device are used to blow pressurized gas into the gas compartment of a bag that is the same bag as bags equipped with gas compartments disclosed in Patent Literature 5 to 7 After blowing in of a pressurized gas, the area near a cutout or a hole in the gas introduction portion is ultrasonically sealed so as to trap the pressurized gas in the gas compartment.
The main embodiments of the invention of this prior application will be described below with reference to the accompanying FIGS. 8 through 18.